Vlf Cable Testing Procedure Pdf

During the test cables are subjected to a test voltage significantly higher than what they experience during normal operating conditions.

Vlf cable testing procedure pdf.

Vlf testing uses very low frequencies as part of an ac cable maintenance routine. The cable tests described below are to be carried out after. Thus it is quite natural for utilities to also use withstand and partial discharge tests as commissioning and maintenance tests for cable. Vlf tan delta and withstand testing of electrical power cables 6 maintenance test a field test made during the operating life of a cable system.

High voltage withstand tests are used in conjunction with partial discharge measurements on solid dielectric cable and accessories within manufacturing plants to ensure the quality of completed cable system components from mv to ehv. There are no rules of thumb to be used. Ieee guide for field testing of shielded power cable systems using very low frequency vlf 1. These numbers result from many years of vlf field use and research.

It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs. The test measures the insu lation resistance between the phases and or between phase and ground. Insulation resistance testing is a non destructive test procedure. Download pdf contact hvi testing summary.

Overview this guide provides a description of the methods and practices to be used in the application of very low frequency vlf high voltage excitation for field testing of shielded power cable systems bach b1 1 and 2 2. Insulation resistance testing purpose. It is intended to detect deterioration of the system and to check the serviceability so that suitable maintenance procedures can be initiated. Dc high voltage testing of new xlpe cables is not recognised to cause cable deterioration however in order to adopt a standard approach vlf ac testing is preferred instead of dc high voltage testing for new and aged xlpe cables.

Vlf testers are smaller and more practical than ac testers but output the same amount of power as a 50 hz mains device. Reduction in cable life. Ieee guide for field testing of shielded power cable systems using very low frequency vlf less than 1 hz. This combination of size and power makes very low frequency cable testing perfect for testing longer sections of cable and apparatus.

Ieee 400 4 2015. Vlf cable test voltages and time durations are set by ieee standard 400 2 2013. Very low frequency vlf withstand testing is the application of an ac sinusoidal waveform generally at 0 01 0 1 hz to assess the quality of electrical insulation in high capacitive loads such as cables.